Question: Solve for $z$ : $z - 28 = -24$
Solution: Add $28$ to both sides: $ \begin{eqnarray} \\ z - 28 &=& -24 \\ \\ {+28} && {+28} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{-28 + z} &\hphantom{=}& \hphantom{-24} \\ z &=& -24 {+ 28} \\ \end{eqnarray} $ Simplify. $ z = 4$